Water resources are already scarce in some regions (like Somalia, shown above), and the IPCC warns that under global warming water resources will only become more strained.

Courtesy Thomas Mukoya/AFP/Getty Images

Mitigation and Adaptation

In its Fourth Assessment Report (AR4), the Intergovernmental Panel on Climate Change warns of the dire future the Earth will face if global warming continues at the predicted rate. As many as 70 percent of extant species may become extinct if temperatures increase by more than 3 degrees Celsius per year. Millions of people may die from floods, droughts, blizzards and other weird weather patterns. Currently arable land will become arid desert, and water resources will become strained.

To combat these dire consequences, the IPCC advises people to take a two-pronged approach toward dealing with global warming: mitigation and adaptation. Rather than serving as a uniting force -- a rallying point for believers in climate change to meet -- this approach created a schism between climate change factions.

Mitigation supposes that people can have an impact on reversing climate change. It also implies that human activity is at least in part responsible for global warming. Anthropogenic skeptics find this claim to be false and opt instead to support adaptation measures.

Adaptation efforts aim to help humanity thrive as a species under the future conditions of climate change. These include relocating settlements in areas projected to become arid land or under water in the next century. Or encouraging the reuse of gray water. Or learning how to farm on mountaintops, where much of the precipitation is projected to occur by 2100. Or keeping an eye on diseases which thrive in hotter climes, like malaria.

Anthropogenic warming skeptics believe adaptation is the key to surviving what they consider an irreversible tide. They believe mitigation, on the other hand, could spell disaster. If enforced, they say, mitigation could actually prevent adaptation.

Mitigation relies on regulation. The IPCC's mitigation measures include, first and foremost, a reduction in the emission of carbon dioxide. Skeptics claim that government-mandated reductions could damage economies by forcing developing countries to utilize expensive alternatives to fossil fuels for their budding industries. If regulations are enforced, and if mitigation isn't enough, these nations won't have the finances to fund adaptation procedures when they're most needed.

Skeptics also criticize the effects biofuel could have on the global food supply. Arable land is valuable throughout the world, and if farmers opt to grow switchgrass for use in ethanol fuel production, food supplies could become strained as prices rose. And those in developing countries eating grain-based diets wouldn't be the only ones to suffer. Livestock requires grain, and an increase in grain prices could also lead to reductions in meat production, affecting richer countries as well.

Then again, livestock requires water -- about 1,000 times more per ton than it takes to produce a ton of grain. So if future climate change reduces global water supply, people won't have livestock anyway. Not to mention the myriad other problems that will come along with global warming, if the IPCC is correct.

And here we reach the reason for the urgency -- and the passion -- behind the arguments on both sides of the climate change debate. Inaction risks future catastrophe. Hasty action may cause present calamity.

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